Extreme pressure lubricant



Patented June 24, 1941 STATES PATENT OFFICE;

2,247,048 EXTREME PRESSURE LUBRICANT Henry G. Berger and Darwin E. Badertscher,

Woodbury, and Francis M. Seger, Pitman, assignors to Socony-Vacnum corporated, New York, N. Y.,

New York No Drawing.

N. J Oil Company, In-

a corporation of Application October 23, 1940,

Serial No. 362,373

9 Claims.

comprised only of a petroleum fraction, isincapable of withstanding the enormous pressures encountered between engaged surfaces in various types of modern machinery, .such as the hypoid gears used in motor vehicles. This fact has led to the development of the so-called extreme pressure lubricant, which is comprised of a suitable carrying agent, suchas mineral oil.

containing a minor proportion of an ingredient which under the extreme pressure conditions encountered will provide or form between the engaged surfaces a lubricating film capable of withstanding these high pressures. Ingredients of the type just referred to are known as extreme pressure ingredients or extreme pressure (E. P.) bases, and numerous materials have been proposed for such use. Among the various E; P. bases which have been proposed and which have met with varying degrees of success are organic materials which contain sulfur and chlorine. Our present invention is related to this general type of compound.

It is a primary object of this invention to provide an extreme pressure lubricant which contains a new and novel sulfur-and-chlorine-containing material or compound capable of giving extreme pressure lubricant properties to a carrying agent such as a hydrocarbon lubricant oil otherwise incapable of withstanding these extreme pressure conditions. ;In this regard, we have discovered that the class or group of compounds or reaction products obtained by reacting various reactive organic compounds with perchloromethylmercaptan are very effective extreme pressure lubricant addition agents. These materials have the advantage of being cheap and easily prepared. Perchloromethylmercaptan it'- self and its low molecular weight derivatives are very efiective E. P. bases, but-we prefer to use the higher molecular weight derivatives because they are more desirable from the standpoint of odor.

The perchloromethylmercaptan, derivatives which we have found to be particularly useful as E. P. bases may be broadly divided into two general classifications: namely, (1) products obtained by reacting perchloromethylmercaptan with organic compounds containing an active hydrogen or an active metal atom, orboth; and

(2) products obtained by reacting perchloromethylmer'captan with unsaturated organic ma terials such as animal and vegetable oils, cracked petroleum stocks, etc. Reaction products of the type encompassed by class (2) above were made the subject of our application Serial No. 177,890, filed December 3, 1937.

Our a foresaid application Serial No. 177,891, of which the present application is a continuation in part, was broadly directed to reaction products of group (1) wherein the secondary reactant is an organic compound containing an active hydrogen atom or an active metal atom, or both. This broad subject matter has now been embodied in another continuation in part of 'Serial No. 177,891: 362,372 filed concurrently herewith.

The present invention is concerned with a group of perchloromethylmercaptan reaction products falling into the broad class designated above as group (1). More specifically, the present invention contemplates extreme pressure bases which are obtained by reacting perchloro- ,methylmercaptan with organic compounds having the general formula RSX, in which Rrepresents a hydrocarbon radical selected from the group consisting of alykl, aryl, aralkyl, and alkarylradiacals and X represents hydrogen or the hydrogen equivalent of a metal. Compounds falling under this general formula include the mercaptans with their corresponding mercaptides, the thiophenols with their corresponding thiophenates, etc. Typical specific compounds are propyl mercaptan; sodium propyl mercaptide; potassium propyl mercaptide; butyl mercaptan; sodium butyl mercaptide; potassium butyl mercaptide; amyl mercaptan; sodium amyl vmercaptide; potassium amyl mercaptide; hexyl mercaptan; sodium hexyl mercaptan; potassium hexyl mercaptan; thiophenol; sodiumthiophenate, etc.

namely, application Serial No.

by the evolution of hydrogen chloride.

disulfide according to the method of Helfrich and Reid '(Joum. Amer. Chem. Soc. 43, 591 (192-1)).

For example, carbon disulfide containing about- .4 per cent by weight of iodine was chlorinated in the absence of direct sunlight at a teperature maintained below 25 C. until the volume ofv the reaction mixture had doubled. This" crude reaction product, which contains carbon tetraa chloride and sulfur chlorides in addition to perchloromethylmercaptan, can be used in the prep-'- aration of the reaction products contemplated by this invention, but it is preferable to purify the crude product by distillation on a water bath at 100 C. followed by steam distillation. Subsequent vacuum distillation of the material refined in this manner indicated that the steamdistilled material was practically pure.

The general procedure for preparing reaction products of the type contemplated herein may be obtained from the following illustrative examples.

Exsuru: Om:

Reaction of perchloromethylmercaptan with amyl mercaptan Perchloromethylmercaptan was. treated with an equimolar amount of amyl mercaptan. The reaction was exothermic and was accompanied The slight excess of perchloromethylmercaptan in the reaction product was removed (steamed out) and the product was dried by filtration. This product contained 22.1 per cent sulfur and 38.1 per cent chlorine.

EXAMPLE Two Potassium amyl mercaptide was prepared by shaking 21 grams (0.2 mole) of amylmercaptan with an equivalent amount of KOH in water. The somewhat turbid solution was added to 37 grams (0.2 mole) of perchloromethylmercaptan in 100 cc. of petroleum ether, and the two solutions were stirred together for one hour at room temperature. There was an initial temperature rise of 5 C., and a water bath was used to prevent'further heating. The petroleum ether solution was then water-washed and the ether distilled on, leaving 45 grams of product which was an oil. This product on distillation yielded a fraction boiling at about 77C. at 1 mm. which contained 25.6% sulfur and 33.2% chlorine.

To demonstrate the effectiveness of the reaction products contemplated by this invention as extreme pressure lubricant ingredients, we have prepared and tested lubricant compositions comprised of mineral oil and typical reaction products of the class disclosed herein. More speciflcally, we have prepared blends of the reac- "from about .5 percent using the oil without the addition agent and samples 01' the same oil blended with per-chloromethylmercaptan derivatives of the type contemplated by this invention.

TABLE I Extreme pressure tests (lbs. failed) Reaction product added Percent EZ A mion'rub i bin? ratio;

8.35 bsJSec. loading rate) None .L 3 ChCSCl-FBIHY] mercaptan a 301 ChC 5gl+potassium amyl merca e 3 Ol.(?SCi+tertiary butyi mer- 29, 000 310 captan 3 30, 000 360' These values were obtained at 1 000 R. P. M. instead of 155. Tb blank oil failed inthe S. A. E. test at 1,000 B. P. M. at a load 01201:;

From the foregoing examples it will be seen that the perchloromethylmercaptan condensation products contemplated by this invention are highly effective extreme pressure lubricant bases. The amount of these materials used may vary to about 20 per cent, but m-generalthe lower percentages ranging from :.5 per cent to 10 per cent are preferred.

Although we have indicated in the foregoing descriptionthat a mineral lubricating oil is a preferred carrying agent for the extreme pressure agent, it is not our intention that the invention be limited in this regard. The invention includes broadly extreme pressure lubricants :containing perchloromethylmercaptan condensation products of the aforesaid type dissolved, dispersed or emulsified in any suitable carrying me- .dium such, for example, as fatty vegetable and hydrocarbon oil .and in admixture therewith a minor proportion of the product obtained by the reaction ofperchloromethylmercaptan with a compound having the general formula RSX, wherein R represents a radical selected from the groupconsisting' of alkyl, aryl, aralkyl, and alkaryl radicalsand X represents an element selected from the group consisting of hydrogen and metal, the said reaction product containing both sulfur and chlorine and being present in the oil in an amount suflicient to increase its load-carrying capacity.

2. An extreme pressure lubricant comprising:

- a hydrocarbon lubricant oil and in admixture therewith aminor proportion of the product obtained by the reaction of perchioromethylmercapta'n with a mercaptan, said product containing both sulfur'and chlorine.

' 3. Anextreme pressure lubricant comprising: a hydrocarbon lubricant oil and in admixture therewith a minor proportion of the product obtained by the reaction of perchloromethylmertherewith a minor proportion of the product obtained by the reaction of perchloromethylmercaptan with potassium 'amyl mercaptide, said product containing both sulfur and chlorine.

6. An extreme pressure lubricant comprising: a hydrocarbonx-lubricant oil and. in admixture therewith a minor proportion of the product obtained by the reaction of perchloromethylmercaptan with a tertiary butyl mercaptan, said product containing both sulfur and chlorine.

7. An extreme pressure lubricant composition comprising: a minor proportion of the chlorineand-sulfur-contai'ning product obtained by the reaction of perchloromethylmercaptan with a compound having the general formula -RSX, wherein R is selected from the group of alkyl, aryl, aralkyl and alkaryl radicals and consisting I 3 X represents hydrogen or the hydrogen equivalent of a metal; and a major proportion of a carrying medium, which composition, when applied to metallic bearing surfaces, will form. a

lubricant film capable of withstanding extreme pressure conditions.

8. An extreme pressure lubricant composition comprising a minor proportion of the chlorineand-sulfur-containing product obtained by the reaction of perchloromethylmercaptan with a -mercaptan, in admixture with a major proportion of carrying medium, which composition, when applied to metallic bearing surfaces, 'will form a lubricant film capable of withstanding extreme pressure conditions.

9. An extreme pressure lubricant composition comprising a minor proportion of the chlorineand-sulfur-containing product obtained by the reaction of perchloromethylmercaptan with a mercaptide, in admixture with a major proportion of carrying medium, which composition, when applied to metallic bearing surfaces, will form a lubricant, film capable of withstanding extreme pressure conditions.

HENRY G. BERGER. DARWIN E. BADERTSCHER. FRANCIS M. SEGER. 

